Wacha baffling hitters with his changeup

Michael Wacha -- 2013 Season

Through 9/19

Since<<

Opp BA

.243

.093

K-BB

56-17

31-6

HR allowed

5

1

>>1 ER allowed in 29 2/3 IP (4-0)

In eight starts since re-joining the rotation at the beginning of September, Cardinals rookie Michael Wacha is 5-1 with a 1.20 ERA. He’s been even better in the postseason, going 3-0 with a 0.43 ERA between the NLDS and NLCS.

One of the primary reasons for his ascension has been the effectiveness of his changeup, long considered his best offspeed pitch. Through Sept. 19, opponents were hitting .213 against it. Ever since, they’ve hit a paltry .094. He is also throwing the pitch more often. He’s thrown it in 24.8 percent of his pitches over his past four starts.

Joe McDonald

Joe McDonald, a native Rhode Islander, joined ESPNBoston.com as a Bruins and Red Sox reporter in February 2010. He worked at the Providence Journal for 18 years and covered the Red Sox, Bruins, Patriots, PawSox and Providence Bruins. He's a three-time winner of the National Sportscasters and Sportswriters Association's state Sportswriter of the Year for Rhode Island. Follow him on Twitter here.